Don't suppress AX events on live regions which just became unignored

BrowserAccessibilityComWin::UpdateStep3FireEvents() returns early
on ignored nodes as well as on nodes which used to be ignored but
no longer are. Given a live region which was ignored but is now
active, returning early results in no announcement being made.

This change only returns early if the newly-unignored node is not
inside or the root of an active live region.

AX-Relnotes: Fixes bug causing some ARIA alerts to not be presented by
screen readers on Windows.

Bug: 1249045
Change-Id: If4b4f95d9cd2b10747ebe1155992732af09aff7b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3452066
Reviewed-by: Daniel Libby <dlibby@microsoft.com>
Commit-Queue: Joanmarie Diggs <jdiggs@igalia.com>
Cr-Commit-Position: refs/heads/main@{#972360}

content/browser/accessibility/browser_accessibility_com_win.cc

@@ -1480,9 +1480,12 @@ void BrowserAccessibilityComWin::UpdateStep3FireEvents() {
   const bool ignored = owner()->IsIgnored();
 
   // Suppress all of these events when the node is ignored, or when the ignored
-  // state has changed.
-  if (ignored || (old_win_attributes_->ignored != ignored))
+  // state has changed on a node that isn't part of an active live region.
+  if (ignored || (old_win_attributes_->ignored != ignored &&
+                  !owner()->GetData().IsContainedInActiveLiveRegion() &&
+                  !owner()->GetData().IsActiveLiveRegionRoot())) {
     return;
+  }
 
   // The rest of the events only fire on changes, not on new objects.
 

content/browser/accessibility/dump_accessibility_events_browsertest.cc

@@ -431,6 +431,11 @@ IN_PROC_BROWSER_TEST_P(DumpAccessibilityEventsTest,
   RunEventTest(FILE_PATH_LITERAL("add-alert-with-role-change.html"));
 }
 
+IN_PROC_BROWSER_TEST_P(DumpAccessibilityEventsTest,
+                       AccessibilityEventsAddAlertContent) {
+  RunEventTest(FILE_PATH_LITERAL("add-alert-content.html"));
+}
+
 IN_PROC_BROWSER_TEST_P(DumpAccessibilityEventsTest,
                        AccessibilityEventsAddChild) {
   RunEventTest(FILE_PATH_LITERAL("add-child.html"));

content/public/android/javatests/src/org/chromium/content/browser/accessibility/WebContentsAccessibilityEventsTest.java

@@ -146,6 +146,12 @@ public void test_addAlertWithRoleChange() {
                 "add-alert-with-role-change-expected-android.txt");
     }
 
+    @Test
+    @SmallTest
+    public void test_addAlertContent() {
+        performTest("add-alert-content.html", "add-alert-content-expected-android.txt");
+    }
+
     @Test
     @SmallTest
     public void test_addChild() {

content/test/data/accessibility/event/add-alert-content-expected-android.txt

@@ -0,0 +1 @@
+TYPE_ANNOUNCEMENT - [Foo]

content/test/data/accessibility/event/add-alert-content-expected-auralinux.txt

@@ -0,0 +1,9 @@
+CHILDREN-CHANGED:ADD index:0 CHILD:(role=ROLE_STATIC) role=ROLE_NOTIFICATION ENABLED,SENSITIVE,SHOWING,VISIBLE
+TEXT-INSERT (start=0 length=11 'First alert') role=ROLE_NOTIFICATION name='Foo' ENABLED,SENSITIVE,SHOWING,VISIBLE
+=== Start Continuation ===
+CHILDREN-CHANGED:ADD index:0 CHILD:(role=ROLE_PARAGRAPH) role=ROLE_NOTIFICATION ENABLED,SENSITIVE,SHOWING,VISIBLE
+TEXT-INSERT (start=0 length=1 '%EF%BF%BC') role=ROLE_NOTIFICATION name='Bar' ENABLED,SENSITIVE,SHOWING,VISIBLE
+TEXT-INSERT (start=0 length=12 'Second alert') role=ROLE_PARAGRAPH name='(null)' ENABLED,SENSITIVE,SHOWING,VISIBLE
+=== Start Continuation ===
+CHILDREN-CHANGED:ADD index:0 CHILD:(role=ROLE_STATIC) role=ROLE_PARAGRAPH ENABLED,SENSITIVE,SHOWING,VISIBLE
+TEXT-INSERT (start=0 length=11 'Third alert') role=ROLE_PARAGRAPH name='(null)' ENABLED,SENSITIVE,SHOWING,VISIBLE

content/test/data/accessibility/event/add-alert-content-expected-mac.txt

@@ -0,0 +1,5 @@
+AXLiveRegionChanged on AXGroup AXDescription='Foo'
+=== Start Continuation ===
+AXLiveRegionChanged on AXGroup AXDescription='Bar'
+=== Start Continuation ===
+AXLiveRegionChanged on AXGroup AXDescription='Baz'

content/test/data/accessibility/event/add-alert-content-expected-uia-win.txt

@@ -0,0 +1,14 @@
+LiveRegionChanged on role=alert, name=Bar
+LiveRegionChanged on role=alert, name=Baz
+LiveRegionChanged on role=alert, name=Foo
+LiveRegionChanged on role=alert, name=Foo
+=== Start Continuation ===
+LiveRegionChanged on role=alert, name=Bar
+LiveRegionChanged on role=alert, name=Bar
+LiveRegionChanged on role=alert, name=Baz
+LiveRegionChanged on role=alert, name=Foo
+=== Start Continuation ===
+LiveRegionChanged on role=alert, name=Bar
+LiveRegionChanged on role=alert, name=Baz
+LiveRegionChanged on role=alert, name=Baz
+LiveRegionChanged on role=alert, name=Foo

content/test/data/accessibility/event/add-alert-content-expected-uia-win7.txt

@@ -0,0 +1,5 @@
+LiveRegionChanged on role=alert, name=Foo
+=== Start Continuation ===
+LiveRegionChanged on role=alert, name=Bar
+=== Start Continuation ===
+LiveRegionChanged on role=alert, name=Baz

content/test/data/accessibility/event/add-alert-content-expected-win.txt

@@ -0,0 +1,11 @@
+EVENT_OBJECT_LIVEREGIONCHANGED on <div#foo> role=ROLE_SYSTEM_ALERT name="Foo"
+EVENT_OBJECT_SHOW on role=ROLE_SYSTEM_STATICTEXT name="First alert"
+IA2_EVENT_TEXT_INSERTED on <div#foo> role=ROLE_SYSTEM_ALERT name="Foo" new_text={'First alert' start=0 end=11}
+=== Start Continuation ===
+EVENT_OBJECT_LIVEREGIONCHANGED on <div#bar> role=ROLE_SYSTEM_ALERT name="Bar"
+EVENT_OBJECT_SHOW on <p> role=ROLE_SYSTEM_GROUPING
+IA2_EVENT_TEXT_INSERTED on <div#bar> role=ROLE_SYSTEM_ALERT name="Bar" new_text={'<obj>' start=0 end=1}
+=== Start Continuation ===
+EVENT_OBJECT_LIVEREGIONCHANGED on <div> role=ROLE_SYSTEM_ALERT name="Baz"
+EVENT_OBJECT_SHOW on role=ROLE_SYSTEM_STATICTEXT name="Third alert"
+IA2_EVENT_TEXT_INSERTED on <p#baz> role=ROLE_SYSTEM_GROUPING new_text={'Third alert' start=0 end=11}

content/test/data/accessibility/event/add-alert-content.html

@@ -0,0 +1,28 @@
+<!--
+@WIN-DENY:EVENT_OBJECT_LOCATIONCHANGE*
+@WIN-DENY:EVENT_OBJECT_REORDER*
+@UIA-WIN-DENY:StructureChanged/*
+-->
+<!DOCTYPE html>
+<html>
+<body>
+<div id="foo" aria-label="Foo" role="alert"></div>
+<div id="bar" aria-label="Bar" role="alert"></div>
+<div aria-label="Baz" role="alert">
+  <p id="baz"></p>
+</div>
+<script>
+  var go_passes = [
+    () => document.getElementById("foo").innerHTML = "First alert",
+    () => document.getElementById("bar").innerHTML = "<p>Second alert</p>",
+    () => document.getElementById("baz").innerHTML = "Third alert",
+  ];
+
+  var current_pass = 0;
+  function go() {
+    go_passes[current_pass++].call();
+    return current_pass < go_passes.length;
+  }
+</script>
+</body>
+</html>